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  <title>显示随机数的最大可能值</title>
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  <div id="layout-content"><div id="function.mt-getrandmax" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">mt_getrandmax</h1>
   <p class="verinfo">(PHP 4, PHP 5, PHP 7, PHP 8)</p><p class="refpurpose"><span class="refname">mt_getrandmax</span> &mdash; <span class="dc-title">显示随机数的最大可能值</span></p>

 </div>
 <div class="refsect1 description" id="refsect1-function.mt-getrandmax-description">
  <h3 class="title">说明</h3>
   <div class="methodsynopsis dc-description">
    <span class="methodname"><strong>mt_getrandmax</strong></span>(): <span class="type">int</span></div>

  <p class="simpara">
   返回调用 <span class="function"><a href="function.mt-rand.html" class="function">mt_rand()</a></span> 所能返回的最大的随机数。
  </p>
 </div>


 <div class="refsect1 parameters" id="refsect1-function.mt-getrandmax-parameters">
  <h3 class="title">参数</h3>
  <p class="para">此函数没有参数。</p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-function.mt-getrandmax-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   返回不带参数调用 <span class="function"><a href="function.mt-rand.html" class="function">mt_rand()</a></span> 时获取到的最大随机值，这可用于
   <code class="parameter">max</code> 参数而不是放大结果的最大值（更少的随机）。
  </p>
 </div>

 <div class="refsect1 examples" id="refsect1-function.mt-getrandmax-examples">
  <h3 class="title">范例</h3>
  <p class="para">
   <div class="example" id="example-3472"><p><strong>示例 #1 计算一个随机浮点数</strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">function&nbsp;</span><span style="color: #0000BB">randomFloat</span><span style="color: #007700">(</span><span style="color: #0000BB">$min&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">0</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$max&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">1</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;</span><span style="color: #0000BB">$min&nbsp;</span><span style="color: #007700">+&nbsp;</span><span style="color: #0000BB">mt_rand</span><span style="color: #007700">()&nbsp;/&nbsp;</span><span style="color: #0000BB">mt_getrandmax</span><span style="color: #007700">()&nbsp;*&nbsp;(</span><span style="color: #0000BB">$max&nbsp;</span><span style="color: #007700">-&nbsp;</span><span style="color: #0000BB">$min</span><span style="color: #007700">);<br />}<br /><br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">randomFloat</span><span style="color: #007700">());<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">randomFloat</span><span style="color: #007700">(</span><span style="color: #0000BB">2</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">20</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
    </div>

    <div class="example-contents"><p>以上例程的输出类似于：</p></div>
    <div class="example-contents screen">
<div class="cdata"><pre>
float(0.91601131712832)
float(16.511210331931)
</pre></div>
    </div>
   </div>
  </p>
 </div>

 <div class="refsect1 seealso" id="refsect1-function.mt-getrandmax-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="function.mt-rand.html" class="function" rel="rdfs-seeAlso">mt_rand()</a> - 通过梅森旋转（Mersenne Twister）随机数生成器生成随机值</span></li>
    <li class="member"><span class="function"><a href="function.mt-srand.html" class="function" rel="rdfs-seeAlso">mt_srand()</a> - 播下一个更好的随机数发生器种子</span></li>
    <li class="member"><span class="function"><a href="function.getrandmax.html" class="function" rel="rdfs-seeAlso">getrandmax()</a> - 显示随机数最大的可能值</span></li>
   </ul>
  </p>
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